SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0253583f1b09d3d845284e45cab418b2cd31e2794decf40bfd08fc5eb3186f67' 
  AND token = 'kRs3qgV3nSQXwZMTDvoVxJcdUhrFOVLh5Mz+2Smidzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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