SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bc5e740cdb6012354ebcbe0bdafcd9083208b83ec0348ee36d3f931a5f90d04' 
  AND token = '5oKdLm60GxEGfJTi0tCk73evtFrJgHlvYoxVxqCK7VI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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