SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c30f2c9870147e165afedbcf2a6fbf1da2cbd830d2d77803b70e2c8e5fd2e39e' 
  AND token = 'dJkcOSX6/mx8R4DkgXNxnwVKSxq8MtWMOzcgrFVa+qU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}