SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a7cf29dea2caf9cae76159b51793a9cfd2e0272f44b8bfc9a3afc81182d50147' 
  AND token = 'UmiEv4xxIFFe/baO0hDy45UzHPw6bSfj/oXC9ZZpT3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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