SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f7264481d5b72d32aa034d83e5be7867119a42cc95355dbe1c872656f6bd9bc' 
  AND token = '2hoYZoOwfsxNHyld2xxOG+34hJ7aTPhOgjwCA5I0Fj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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