SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f683f13ba94ade65e68cc5e6188c8c9c7c6ccd4dc424a20b280661b2248774f9' 
  AND token = 'lC8hObqRkWP9ZWgfmcjNGPWvulk04IfbbvdVIPY5TRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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