SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9902115f942890e3bce53ff142da154ebaf91fcbc50acc97e80b7bd0faad5501' 
  AND token = 'aoTCk/wfBGTUoXUzg1frN5DQ0/x5gNOSarGOdujYQRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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