SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4118c4c7d791b56e17c285d8f76cda79be2cbb794ed98f77f09bafc18dad4235' 
  AND token = 'zLR3aEZi3Lf+axPCV42GOqCzsgM6tjNKJb94gPj/Q3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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