SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b85270467f4dbb2f7f95937f752cb2fb7f231d9d1ee91c435081df68a2ac45ef' 
  AND token = 'xe+YSJ8iemOFKQD1mUOY6uwQ06U9BjPglaD9ZQb9p68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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