SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b353c4bd88e1ebb2fb548983a2be3964362a5e22932fe98b96ebc6edd37a584' 
  AND token = 'GrI2jJ8RwIJ2Gry35P9a3x2xhn+H1rbUYySlZPftqEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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