SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1c2afee7fa8e6a78a29cc7304a34490694f49bb80cba2dda8172531d484733f' 
  AND token = 'bl+hGWQYWPB2v2JpM/GdEF4dNDHs999hlSYY7ZLVY1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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