SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9d67ffd7b48fec6d128406075deeb528d224d4ecef7ddcd3634e9cab0033648' 
  AND token = 'fKhATLgC+aJPX+bSGu6TpcFO4tTRK0HffUtZGXpSwUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00073

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}