SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ba99e2679ed97e27aa00210d54f2466d42b4727fe041df0bffee74a347d428f' 
  AND token = 'NLqbHcEwsBCY0cUerYJuXUeQxPN0H7uzUVH7sH+GHv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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