SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30e86833d72a7fe88fbf57f147d5b61264eb3abd47822b42a3faada9b7b39071' 
  AND token = '1ooANzcB5PsRLwCaqtRWg7jGG+4WVxVzOZ+tVC017K4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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