SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd233779a64496127776e5b8111d55c56c051814f4fd388a99642d1daeb226bf9' 
  AND token = 'mmi/lQgnJsLtnGO1YQXpfKp0q5bee6T4Z+iAgzu1BZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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