SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0727e0051d4ea239b93dd695a95f223c88048c16d607a6a8a0701d504b9627f' 
  AND token = 'hQ0NJ3O7DCuRuXeUfI3riDYXQU1WOTek57+RIpgRgI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}