SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33700539c6b87bc09837f9ed9f800a7cf542ee4f182439d96bd0ea99706fd13b' 
  AND token = 'PbFdVyWtFVe19wwbIRRkbfcgGy7sY0rk/qYQVLBLFcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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