SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a477213051d7fd31d58f2f9bd3df616e4306d8600d2db8fb811a5eefcdfd7684' 
  AND token = 'fR9UTv//igOmDqK/bSHrN6r+rYhX770ZzNLWVSW3jzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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