SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ad2ca01054cdde5c4d779d98666605ee5a727c47197585766c220c389569ff2' 
  AND token = 'SioazKjz9ZhuoUxQVpZuVT4tjD86lGgxf4WMl5/43I0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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