SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bbf752469122588495d2a9a9624671e99d027fa5d33c01f5ea70e8ed9743a427' 
  AND token = 'hTUGCQL6d8gtRqquFTEJwnGGUk5kzMySAtyzn4X5IWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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