SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a44189086e90ac682d43bf12e25576ecf858f37a9f3738d7bacdea3415367984' 
  AND token = 'O/qZK3lNThA3U6IhhNzEKSSCzrsWJlSCGa9P0DJQL3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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