SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fdfb5b49cf66f8f3b4fe84b2720135fb5cd0290a6130eef2a5079e8ab6f9ef0c' 
  AND token = 'LvjlYNmFZsv7y11cMV7dWSzW+jOUeskmYy5AEERhUnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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