SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '97e1c52ee41e97733f76ef9b5a4fb18dd58a64ddef6801ab3f884d7a74152f74' 
  AND token = 'V7ZRQekGLzEY59YO+phytvMVUHpjv0HAoo518Y43S8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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