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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8e4cfa8ee823f8c24ae7b06f6bb685e60a8def0aa6e4edba7486cf9be8a9f2a' 
  AND token = 'nkTeYOGrAfqvwjR4iEnc9qAlcxmdl0f2l0uAGbDxIJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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