SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '498dc003a5d1b0685863148c945a10c3c7b59975c01c7d0c8574981a4af66cde' 
  AND token = 'vZs5DRBcMIDUJffXVIwx4VXqPM3jWzkKzUpAmLzseSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}