SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52bb1da1f87969f1eafe97801656bd7455fe4431ade75f57be72808024627fb5' 
  AND token = 'wvYFRgdLJSJKXcE7gRqncuAQ4OFjoFL1Iy8VryeLngw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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