SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '027e86fa8bb2f27e3a61ab698f8b8694096f2facb440fdfa6886ee3fb5fb1292' 
  AND token = 'rBu5qyIhP4+OyrEN/YjxAua0HEecv5of50TV4BIBqYY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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