SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24e04f82985cef58a9a1c61a1b71456f05e593edc0677ebb2f91fb5db65923de' 
  AND token = '3iKzqLFUFhPjJW0mtY/SCn+fL6uF/gdhlkHwVFtF7I4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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