SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bc681b1c48c563cba996a9e19ea1c556420182a84941f649469e929bdd20b7c' 
  AND token = 'wCqxK7bKJmYzHOT9DR8PjA11KhOXDB+2H/zHMijpzng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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