SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f48ac8b722cf14e92b93e8f3828f60ad6ba6c767b134f5cfe67d0d597b34fc9c' 
  AND token = 'jndLRyvmD1XohpCTZhzSiIHsdJp7tgwaoiwdjgWq98M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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