SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b6678d6aaa8fc7833e1f7ee3c9bddf95840569f08acba3297647fc0ff9171a0' 
  AND token = 'nlRtOQzyqmd/9Bf9EmfRuReBTO/mvN44NZLU/XHLT3A=' 
  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"
    }
  }
}