SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c13804c5843f1e5c61817ab51910060f2f290d9329a00a863fdd74b1df324fd1' 
  AND token = 'a67l8rLaEvSBgPZzXVoqEvY9vyyjLDHY+1Xh71jPKVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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