SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '148d1cb10250971070c83ecf69a0bf23ad6e73dc543c0caf2bd437fcf347aeb7' 
  AND token = 'SdlFx2mDoXHoYpizSruB4+4ellYZTSLRYoSLmFTzXSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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