SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e45decdaa0702b3cf9b46fdf10b474b14e2673283b88e19394a6371410af2e3e' 
  AND token = 'm984whIrs9xT7LZGxj1FoOZvcXJa9Lg4UR5yyVgHSkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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