SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c901fc64f7b905fc7581e5ef30fcf0901fb481e80510deef2f88be2ff322e307' 
  AND token = 'LAVG4oNOuT809leU2MMXLsZabt0irFTjRPom6VEqmAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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