SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6bc8b3724689381ec1e7e51d6ba34f72d5b3405796680b06173f64061a108ec4' 
  AND token = 'B15HAbpWkvt+wN0qChYBuh8JQSly1NRqxy4QVF8Im+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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