SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '70f833e9d911ea632786fd841f30476f94f65a4019a0adaeadf16cf516d08816' 
  AND token = 'IYWHBHXOrSkswyihVqOD2KXt+nE7/FCXoZwaeR8qSqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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