SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1df1ade3402b74ac5acf8bcaf380ebfcbdd25e62c8768f7aad31d1cb5efbfab' 
  AND token = 'VaetxP7L2Ewzyxe2Vyhq9q032N6ZsFKmhugFhl6UffQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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