SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6aaf0dd9d97222015672bf9357924e51e6688cecb3542c68def54e786182e767' 
  AND token = 'MZx4VmeBfOmZ9RSZoWehhT9LBVcYh/8NJJZgmwjc8G0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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