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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6630a28a8d61a43b46440e1dd192c4cdd52f47cd4cc06542dd3be3ff21b7da7' 
  AND token = '+qvzM6OcZvWW9yXdvdM5pWBrYpXIQ3Z0IB5Fv3zSAqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}