SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b3f69705532e777810adb4ba632c69ea085645cc1403f73f40e973372e2a5a4' 
  AND token = 'QDCS2b8gTv4YbjdTlTTvBuhUd9tz/ZVsLXI84Ft9WWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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