SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46c9868fa97195a05f7c5e906fba2f4e1a7ba1118023ebe339f82b26dca86bcd' 
  AND token = 'X2sTbiNjvVfmLIrcSbIo/FMOhd7LqAcojJ7nCoLlVBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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