SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4712fbfdb541b013b642d0e19f6a2451e883ac53eaa0cd930ba3afed71e6c5a' 
  AND token = 'zxwGjOWvPuHjayHFmI3A9W5dYv01PDGcWjjCLCbCVvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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