Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03d388fbbe4afc620f54d7699c0912b7d0081dc75948b7ec78e992e1776b9a06' 
  AND token = 'k4ynuQ5T+I9UqqL7FW8mRhWHIEzQqAl+dyZFSixH2U0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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