SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b57c80778d9d7fe6ca3e73fde9e5ca23e7ab3a7e51f52fb451805794fa4b5fd6' 
  AND token = 'dyCExRQ0DlwB1uNv9hIsKtz6vEjwlBAYGw7MI/1UiWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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