SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bed734aafc625034307f47cef51a8381f928d6e50a6c83a32cacb130d4a3abc' 
  AND token = 'YC+WDLzOHuMVs1Axl9gKFG+E5jsMjOKWcmbDUHCYLV8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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