SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de06994db1f838d1df580ea4198da436ad5ffca7b1925fe325942ff02c2606c1' 
  AND token = 'MPMEXNa+B3KNsfrphvkx+YCp0OdS3Mr/ByFqGNblDVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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