SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f377940d1057d9911c993375d1ae4c2ec639b8350830e23d605f3a83194376fc' 
  AND token = 'x2pvR+4+/KjuP4zyPTUFfhFY9TjrAj3LTKlvkWtr+I8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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