SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '813bd04c5a6a2718cf164db36e4fc5515ea63e618748718b89e1b6a5627b4435' 
  AND token = 'qCB7C1hKO/oKGR3V4sZBWtYPMFT4gOCh03Qr4ybhKl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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