SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbfd96a4c39cf68e657a5052506602ca038671d49b5ba2e16602bd95762b7810' 
  AND token = '/pzt5Lzg9YeCmA9AHhfBmpjp880ZQnWDGlNOkf+dshk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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