SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '13759ef450ad6be9aa69ec57632d970b23dc9aedf1423a285b36987a94461802' 
  AND token = 'b/x9KChIEbo8HxZlEpbgvVkhOPrhhkQ4Gq6xYNJ+Y28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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