SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e925d4814f7bf90158db08da6c77e339211988b7569be3d1699b038258409986' 
  AND token = '5jsmX8NYYXiqAb7LqCJ+UWPdGOAmZVSpeNVRGQJTElU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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