Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6304a83a5f5c582c563dced0200a39ad7b29e1c8eae3fa5e942d95cfd44dc1fa' 
  AND token = 'Lrw4Fk8NdS5wHuWLAaqTqlDkbhmzdK3fOwjTXlvqGqw=' 
  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"
    }
  }
}