SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4e80aa7432db009737731bb82f97e2415cef05e000b6dcd25e2eb15666b99f4' 
  AND token = 'zlZqTV87qiBIBg22SON+cvF7aXrwAk9dmxZtfhG3FaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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