SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff064506fa18177acd447eb3710532e6d3d74f6b7765fef602f8522a4b854c53' 
  AND token = 'qxigk5BZ0pzX3+gIMcJvKPBTPsbMfgs1j9wpqnCuDng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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