SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16963eaf7b38208ce501e206a0c3e5ca9611865ac7ee11d6ab8e0df374d020f1' 
  AND token = 'RsmCNu/FV/gwpQDwGLpODuU358H5d/jg46Nv7M9KuqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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