SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9d1a6753c0e8ca3646aedb0c32725388fa9d07b7bf1f7af862d61fe5546a1ce' 
  AND token = 'cppsM0Aorl7cPIpiHAO/CK4uCQftjSTWfCTJfDbUtmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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