SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1393d1a378347d1fbe00b89f7cdea04564815eba280b54b0f68dc99f1b3c059' 
  AND token = 'gKpvT9Twc1DmilIPCHc2h+aMIQsMHrWh6edNTCgprHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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