SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a784a5000950aa0dfb40565209459c7af3d7206a49d3bcd33573726839117885' 
  AND token = 'HBG5Vq6gFmMGGVCf6eSELEoAACsPKPJJ6qHjQPWApyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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