SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6eeb28d239adf2f58b76b75975fffbab081a05de3caad5766a96529e9363e08' 
  AND token = 'ty3H2lFAuZuTEEhSMiHRZImbL+cVCyaHyx3YRJrRGc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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