SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7734c2a67a1f618cb9084a14a7834d0524e66f8750acda60791ec581edc958d4' 
  AND token = 'V0/Je7dVC9QofTiKGlmywnlRVQr++8TfuVUrR7LmHPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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