Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83e36afb0ca74d4f4fac5fa9b7b3fd1b4e1fc37b9cb92cd1b16c1468551995b9' 
  AND token = 'KdJAwqPY50HOHp26IxM4lAKoHPg16D2tliDoxeAFzcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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