SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b85893995e650c7c6debf34c37530a54a30f0cdab17273748fcb1b15009a561d' 
  AND token = 'vRonuwVrl4qMhpNIabkIZ+mufbgAwgo4C7RSiGrJdXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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