SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e16bcdf27c9129d4d3884c575f8a2bbba0e01cfe95fcd6b342c840134a70aa7' 
  AND token = 'c67cYbO5lS+NodWtIDfzUSd5gKRqcv5ZIAPPhMTgamQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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