SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c8269251028473160f505c7f73623d9a7ff0ba0c13d4a46ce67e10a289579310' 
  AND token = 'pqyqR+pJEgEdKIUk+Zrwng8uSAMNZgLIN6uJVJGSeR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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