SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fa4dd5f0c4e10d6b571050483e1e6cdf43ff9720f49879256c2d23d212b60b0' 
  AND token = 'hJnNMKtgMc3kN/otVtOwm0osmODGXi2iCN88zv38Rbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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