SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ecb51722199eb5507d79b101c57ee47caeeaa1a64a3c854047ec13c065f5922' 
  AND token = '/0oK/vja48+aTAVGmn+VWuFm3bkuDBO5G6f4mNlYDK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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