SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78577031b338086da849819130f1bd1efd9326eba3097a1d61ce5209bbc7f735' 
  AND token = 'tV9I64QXmtw3GNUGhi7eofN89vYCNtHUT8RrKYXglFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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