SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef011e4f3dcd90eaa5de6f8528b9347440d225cc8895f542fb0dc6fefada9dc3' 
  AND token = 'xGZtJa5L/lWDaFiaXo4v97nnpIQnlMEi4GylCKBJoEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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