SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'da4a8b2f9606461efc9973bbdd29d2f04f4851e77da6b9b0ff6c085b9c03b228' 
  AND token = 'Zf2Drv+r3Ge6ITKLcNK95+aLoZKokjXObVzYp6IiKfg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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