SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84e73747f701fbf3acd55872f5bf6c07c106289986b8377c703f55bd9caadcad' 
  AND token = '6jU7IoqJ/V7ikfyRgbAWRhTdxQDl+CM4rq8IqCmJxmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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