SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e67e6813c42d972306928cfaa651553f4fe15d4bf5e1be280e80e9014943400e' 
  AND token = 'WJIeZ2R5xz8YYs/9Yh7C+f4q/qNQFVAJOCflRvT0htA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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