Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5478c9121f7e998691d9dd000c91003c086ac70afcb96986b00022cacf948fc8' 
  AND token = 'ZDRLNkcjUIl15uzIhdcm5bnGPBIzjmDHpY8zI4q/DwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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