SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e67ed63e3ed969cb67298e6eda70223339e363c815d97852caf9d4f2c043f208' 
  AND token = 'F5FRrzWihTafqrC8YyHp01QTsPVIhYjKG2bbkIKhfLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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