SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '612c1b57511d7f03bda5664bd7913933cde01d2f8fc887bd9d9f6431ae7a1186' 
  AND token = 'ZQYgXI3NovAdIYNSel7Wj9sDrUcjGZ5bcEFni2zgCFg=' 
  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"
    }
  }
}