SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a0270fd97f8dd63951c861f2e7f11a53462a9da28b145d58b740440f9ac7d3e' 
  AND token = 'Uy+elh4811doUjYw/XzXm/cg6nNu7Xdj+hiN6qw+l9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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