SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '926beff4346cdb5828cb29b331d2537ef72e94b680e99fbb7cf91b410446dec9' 
  AND token = 'i3UnJZZu3PveJhMU/fxyI3pY4uj59fLRPDo6YJlR0zw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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