SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '139e8a990ceb17fab84ff962531f3881b7a3bf897b13737acad83c1765106130' 
  AND token = 'Ti1pc4Ua3wFs5/3K7RuE1Et0QDoOKhOQ9H4hVCALUlM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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