SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99b8bc3d7ea167336d0cd2410ba2813066a82b7f47bd4f2793566e5b0efb8df2' 
  AND token = 'OYS/XgHtEcHfMV7grQXjYXJuC8Ga0CWIUjQoe8MdoLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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