SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b294389f92ef701a53873433f63d8f8edb27c6bf46a0e55d172427a3a433eefe' 
  AND token = 'JRrVkY6gMdNQ2c3t+qLGBxVTdJkL1hXOVxS11vWFUZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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